Sewing machine



July 29, 1947. F. w. BREUL I 2,424,793

SEWING MACHINE V Filed Sept. 5, 1945 s Sheets-Sheet 1 July 29, 1947. F.w. BREUL 2,424,793}

SEWING MACHINE Filed Sept. 5,1945 i s Sheets-Sheet 2 will- JreaLz ic ZZZ.l reu/Z v l/gy.

5 Sheets-Sheet 3 SEWING MACHINE F. w. BREUL.

Filed Sept. 5, 1945 July 1947.

Patented July 29, 1947 SEWING MACHINE Fredric W. Breul, Bridgeport,Conn, assignor to The Singer Manufacturing Company, Elizaboth, N. J., acorporation of New Jersey Application September 5, 1945, Serial No.614,495

16 Claims. (Cl. 112-160) This invention relates to improvements insewing machines and, more particularly, to sewing machines havingwork-surging mechanism for periodically indenting an edge of the Workbeing stitched, thereby to produce in the work a shelledge efiect.

The primary object of this invention is to provide a sewing machine witha simplified workedge indenting, or surging, mechanism adapted to lenditself to high speed operation of a sewing machine.

The invention has for a further oject to improve the work-feeclincharacteristics of a sewing machine provided with a work-surgingmechanism.

Another object is to provide a substantially unitary work-surgingmechanism which may be readily applied to a standard type sewing machinewith a minimum of alteration and expense.

With these and other objects in view, as will hereinafter appear, theinvention comprises the devices, combinations and arangements of partsdescribed in connection with the accompanying drawings, which illustratea preferred embodiment of the invention and in which:

Fig. 1 is a front side elevation, partly in vertical longitudinalsection, of a portion of a sewing machine containing the improvedwork-surging mechanism. Fig, 2 represents a transverse vertical sectionof the bed-plate of the machine, the section being taken substantiallyon the line 2--2 of Fig. 1. Fig. 3 is a bottom. plan view of the sewingmachine; a portion of the bed-plate being broken away. Fig. 4 is abottom plan view of the presser-foot of the machine. Fig. 5 is a detailview partly showing the presser-foot and feed-dog in side elevation andthe throat-plate in section. Fig. 6 is a top plan view of a portion ofthe bed-plate of the machine, with the coverplate of the surgingmechanism housing removed. Fig. 7 is a detail view, in front elevationand partly in vertical section, of the surging blade in its advanceposition with respect to the presser-foot of the machine; the section:being taken substantially on the lin 1-4 of Fig. 8. Fig. 8 is a topplan view showing the surging-blade, its carrier-block,- thehemmer-attachment and the work; the presser-foot being illustrated indot-dash lines.

The present improvements have been embodied in a lock-stitch sewingmachine of the class disclosed in the United States patent of S. Zonis,No. 2,267,581, December 23, 1941. The

sewing machine has a frame including a bedplate H), from one end ofwhich rises the hol low-standard H of a bracket-arm terminating in ahead l2. Journaled for vertical reciprocation in the head His aneedle-bar l3 carrying at its lower end a needle M.

The needle I4 operates through a suitably apertured throat-plate l5,secured upon and forming with the bed-plate I0 a work-support. Disposedbelow the throat-plate l5 and complemental to the needle l4 in theformation of lock-stitches, is a rotary loop-taker N5 of the rotary hooktype and having a thread-loop seiz in beak IT. The loop-taker l6 rotatestwice for each needle-reciprocation and casts the needle-thread loopsabout a mass of under thread contained in a thread-case l8 journaled inthe loop-taker and restrained against rotation therewith.

The loop-taker I8 is suitably secured upon one end of a horizontallydisposed loop-taker shaft I9 which is rotatably journaled in spacedbearings 20 seated in a horizontally apertured bushing 2|. The bushing2| is secured by a screw 22 in a wall 23 depending from the bed-plate10; said wall 23 forming a portion of a gear-casing providing alubricant-chamber 24. At its end opposite the loop-taker Hi, theloop-taker shaft l3 carries a spur-gear 25 disposed within thelubricant-chamber 24.

In mesh with the spur-gear 25 are teeth 26 provided internally of aflange 2''! of a driving gear-wheel 28; said gear-wheel 28 beingdisposed in the lubricant-chamber 24 and adapted to dip into a supply oflubricant contained in said chamber. The driving gear-wheel 28 issecured by a screw 29 upon one end of a horizontally disposed bed-shaft30 which rotates once for each needle-reciprocation. The bed-shaft 30 isjournaled, adjacent the gear 28, in a bearingbushing 3| secured inanother gear-casing wall 32 depending from the bed-plate II]. Adjacentits opposite end, the bed-shaft 30 is journaled in a bearin 33 seated ina lug 34 depending from the bed-plate I0. Suitably secured upon theoutboard end of the bed-shaft 30 is a peripherally grooved pulley 35engaged by a driving belt 36 of the sewing machine in the usual manner.

The work is intermittently advanced across the work-support iby adifferential feeding mechanism including a main feed-dog 31 and anauxiliary feed-dog 38, both of which feed-dogs operate through suitablefeed-slots provided in the throat-plate 55. The main feed-dog "l engagesthe work entirely rearwardly of the path of needle-reciprocation and theauxiliary feed-dog 38 engages the work entirely in front of theneedle-path. The main feed-dog 3'! is suitably secured upon ahorizontally disposed main feedbar 39 and the auxiliary feed-dog 38 issuitably secured upon an auxiliary feed-bar 46 disposed substantiallyparallel to the main feed-bar 39; said feed-bars extending crosswise ofthe bedplate Ill and being respectively provided at the forward endsthereof with forks 4| and 42.

At its rearward end, the main feed-bar 69 is pivotally connected to theupper end of a rocker 43 rising from a main feed-advance rock-shaft 44disposed horizontally below the bed-plate H) to extend lengthwisethereof. Engaging the opposite ends of the rock-shaft 44 are pintles 45adjustably secured in lugs 46 and 41 depending from the bed-plate I0.Secured upon the rock-shaft 44, adjacent the lug 41, is a dependingcrank-arm 48 connected by a pivot bolt 49 to a pitman 59 having a strapembracing a feedadvance eccentric adjustably carried by the bed-shaft30. The rearward end of the auxiliary feed-bar 40 is also pivotallyconnected to a feed-advance rocker 52 rising from an auxiliaryrock-shaft 53 disposed rearwardly of and substantially parallel to therock-shaft 44. The rock-shaft 53 is pivotally supported at its oppositeends by pintles 54; one of said ypintles being adjustably secured in thelug 46 and the other of said pintles being similarly secured in anotherlug 55 depending from the bed-plate l9. Adjacent the lug 55, therock-shaft 53 is provided with a depending crank-arm 56 connected by apivot-bolt 51 to a pitman 56 having a strap embracing an auxiliaryfeed-advance eccentric 59'adjustably carried by the bedshaft 3D. Theeccentrics 5| and 59 are disposed adjacent each other upon the bed-shaft39 and are generally similar in construction to the feed-advanceeccentric disclosed more fully in the U. S. patent of W. Myers, No.2,128,031, August 23, 1938.

The bed-shaft 39 also carries a feed-lift eccentric 60 which is embracedby the strap of a pitman 6|. The forward end of the pitman BI isconnected by a pivot-bolt 52 to a depending crank-arm 63 at one end of ahorizontally disposed feed-lift rock-shaft 64 mounted on pintles 65which are adjustably secured in lugs 66 and 61' depending from thebed-plate |0. Clamped upon the opposite end portion of the feed-liftrock-shaft 64 are the split hubs of two feed-lift arms 68 and 69; thearm 68 carrying a roller 19 engaged by the main feed-bar fork 4| and thearm 69 carry a roller 1| engaged by the auxiliary feed-bar fork 42.

From the foregoing description, it will be understood that four-motionmovements are imparted to the feed-dogs 31 and 38; the feed-dogs beingraised and lowered in unison by the described connections with thefeed-lift eccentric 69, while the work-advancing and return movements ofsaid feed-dogs are derived from the adjustable eccentrics 5| and 59. Byadjustment of the respective eccentrics 5!, 59, the feed-dogs 3'1 and 38may be caused to have unison workadvancing movements, or eitherto fullor stretch the work by imparting differential movements to the twofeed-dogs.

In accordance with the present invention, the flange 21 of theloop-taker driving gear-wheel 26 is externally provided with spiralthreads '52 to form a worm in driving engagement with the teeth of aworm-wheel 73 which extends downwardly through an opening 14 in thebed-plate IS. The worm-wheel 13 has its hub 7.5. secured by 4 7 screwsIf upon a cross-shaft Ti extending trans-' versely of the bed-shaft 3i]and disposed above the bed-plate Hi. The cross-shaft H is rotatablyjournaled in spaced bearing-bushings l8 and 19 secured in suitablyapertured bosses formed in a generally rectangular housing bracket 96;the bracket 89 rising from the bedplate I9 and being suitably securedthereupon by screws 8!. The top portion of the bracket 66 is closed by acover-plate 92 secured by screws, as 83; the joint between the bracketand coverplate being preferably sealed by a suitable gasket.

Also secured upon and for rotation with the cross-shaft ll, within thebrasket 89, is an eccentric 84 embraced by the strap at one end of apitman 85. At its other end, the pitman 85 extends between and ispivotally connected by a pivot-bolt 86 to the laterally spaced crankarms81 of a, rocking sleeve 89 journaled upon a stub-shaft 99 which issuitably secured in the front and rear walls of the bracket 89. Thesleeve 88 has a depending arm 99 which is forked to receive one end of ashort link 9| pivotally connected to the arm 9|]. The link 9| iscorrespondingly connected by a pivot-screw 92 to one end of ahorizontally disposed and endwise reciprocatory slide-bar 93. Theslide-bar. 93 is journaled in an internal bracket-lug 94 and an externalbracket-boss 95 for reciprocation transversely of the line of seamformation of the machine; said slide-bar 93 being disposed above thebed-plate l9 and substantially parallelto the bed-shaft 39. I

Secured to the end of the slide-bar. 93 proximate to the path of needlereciprocation is a carrier-block 96 having horizontally parallel upperand lower faces and provided longitudinally of the slide-bar with avertical slot 91. Clamped by a bolt '98 to the carrier-block 96 is anedge-- wise vertically disposed work-edge indenting element orhem-deflecting blade 99 having its shank located in the slot 91 andterminating in vertically spaced ears I99 straddling the carrier-block96. The shank of the blade 99 has a slot |0|Z elongated transversely ofthe line of scam formation and entered by the bolt 98, thereby providingfor adjustment of the blade lengthwise of the slide-bar. As illustratedin Fig. 'I, the lower edge of the blade 99 is substantially in contactwith the throat-plate i5 and the upper edge of said blade is downwardlyinclined toward the free end of the blade, thereby to provide a narrowedwork-engaging edge.

The feed-dogs 31 and 38 are opposed by a presser-foot sole-plate 192having a needle-aperture I03 disposed rearwardly of and forwardly opento a blade-clearance slot H14 provided in the sole-plate to extendslightly beyond the needleaperture I93, as shown in Fig. 4; said slotI94 being disposed in alinement with the blade 99. The under orwork-engaging face of the sole-plate I92 is preferably laterally steppedby cutting it away throughout the length thereof and from theblade-entrance side of the sole-plate edge to the remote side of theneedle-aperture I09, to provide a work-clearance recess I95. In theregion of the sole-plate slot I04, the recess I05 is enlarged to form awork-clearance notch |96 preferably extending across the entire width ofthe sole-plate. The sole-plate N12 is pivotally attached to thepresser-foot shank i0! which is secured by a screw I08 to the lower endof a presser-bar I69 endwise movable in the bracketarm head I 2 andspring depressed in a conventional manner.

- work-edge indenting mechanism.

Disposed in front of the presser-foot sole-plate I02 is a conventionalscroll hemmer Ilfl havin its shank Ill adjustably secured by a screw H2upon the bed-plate ID. The delivery end of the hemmer III] is located todirect the hem-fold H, formed by the hemmer in the work W, under thesole-plate I92 at the recessed side thereof.

In the operation of the machine, the slide-bar 93 performs one completereciprocation during the formation of a plurality of stitches, as forexample six stitches. During its advancing movement, the blade 99 entersthe presser-foot slot I04 and deflects the edge of the hem-fold Hinwardly sufficiently far to cause the needle M to descend outside thehem-fold and thereby form a stitch extending over the edge of the work.The forward feed of the work, in connection with the action of thepresser-foot, the return movement of the blade 99 and the resiliency ofthe material being stitched results in the needle again penetrating thework in its subsequent descent and until the hem-fold is again deflectedby the blade 99. Consequently, the stitched work presents a scalloped orshell-edge appearance, as illustrated in Fig, 8 of the drawings.

As may be best seen from Fig. 4, the horizontal work-clearance notch I06is located intermediate the ends of the presser-foot, thus to divide thesole-plate into a, forward portion I02 and a rear portion I02. From Fig.5 it may be seen that the forward and rear portions of the sole-platehave respectively cooperating therewith the feed-dogs 38 and 31 whichare disposed in tandem relation beneath the presser-foot. Thus thefeed-dog 38 is effective to feed the work beneaththe presser-foot andthe feed-dog 31 is effective to carry the work from beneath thepresser-foot.

When the work-edge indenting element 99 is employed, it has a tendencyto place the work which is beneath the presser-foot under a strain andthus stretch the same as the work is clamped at both the forward andrear portions of the foot. Therefore, the needle, being disposeddirectly behind the work-edge indenting blade, penetrates and formsstitches in the stretched portion of work. When the work is free of thepresserfoot it will then have a tendency to pucker.

In order to obviate this objectional puckering, the present feed-dogsare timed so that the forward or auxiliary dog 38 is given a longerstroke than that which is imparted to the main or rear dog 31. Theforward dog will then feed the work beneath the foot faster than therear dog can feed it away, and therefore, an abundance of work will bedisposed beneath the foot, Thus, when the work-edge indenting bladeengages the work there will be no tendency to stretch the same and thestitches will be formed in an unstressed portion of the work.

It is to be understood that the above noted housing bracket or frame 80,when detached from the sewing machine, contains the entire In order toadapt a standard type sewing machine for receiving this substantiallyunitary structure, it is only necessary to provide the bed-plate I9 withan aperture 14 and to furnish the machine with a special presser-footand a, driving gear-wheel 28.

Thus the present work-edge indenting mechanism comprises a substantiallyself-contained unit which may be readily applied to a standard typesewing machine without involving any great expense or undue effort.

The described hem-deflecting mechanism is structurally simple andcompact, and is particularly well adapted for high speed operation, asthe mechanism housed by the bracket is constantly and adequatelylubricated by the oilthrowing action of the driving gear-wheel 28 whichcomprises an actuator common to the looptaker and the hem-deflector,

Having thus set forth the nature of the invention, what I claim hereinis:

1. In a sewing machine having a frame providing a Work-support, incombination, a reciprocatory needle, a rotary loop-taker complemental tosaid needle in the formation of stitches, workfeeding mechanism, awork-edge indenting element mounted for reciprocation crosswise of theline of seam formation in the region of the path ofneedle-reciprocation, a rotary actuating shaft disposed below saidwork-support, a driving member carried by said shaft, means operativelyconnecting said driving member with said rotary loop-taker for rotatingsaid loop-taker at a speed greater than that of said rotary shaft, andmeans operatively connecting said driving member with said work-edgeindenting element for reciprocating the same.

2. In a sewing machine, in combination, a reciprocatory needle, a rotaryloop-taker complemental to said needle in the formation of stitches,work-feeding mechanism, a work-edge indenting element mounted forreciprocation crosswise of the line of seam formation in the region ofthe path of needle-reciprocation, a driving gearwheel, means forrotating said gear-wheel, operative connections with said gear-wheel forimparting to said loop-taker a, plurality of rotations for eachreciprocation of said needle, and operative connections with saidgear-wheel for imparting to said work-edge indenting element a less number of reciprocations than are imparted to said needle.

3. In a sewing machine, in combination, a reciprocatory needle, a rotaryloop-taker complemental to said needle in the formation of stitches,work-feeding mechanism, a work-edge indenting element mounted forreciprocation crosswise of the line of seam formation in the region ofthepath of needle reciprocation, a driving gear-wheel, a pair of drivengears in mesh with said driving gear-wheel, means for rotating saidloop-taker from one of said driven gears, and means actuated by theother of said driven gears for reciprocating said work-edge indentingelement.

4.. In a sewing machine, in combination, a reciprocatory needle, arotary loop-taker com-- plernental to said needle in the formation ofstitches, a rotary loop-taker shaft, work-feeding mechanism, a work-edgeindenting element mountedfor reciprocation crosswise of the line of seamformation in the region of the path of needle-reciprocation, a rotaryactuating shaft, a driving gear-wheel carried by said actuating shaft,said gear-wheel having an internally toothed flange externally providedwith a wormthread, a pinion-gear carried by said loop-taker shaft inmesh with the internal teeth of said gearwheel, a worm-wheel engaged bythe wormthread of said gear-wheel, and means actuated by said worm-Wheelfor reciprocating said workedge indenting element.

5. In a sewing machine having a frame providing a work-support, incombination, a reciprocatory needle, a rotary loop-taker disposed belowsaid Work-support and complemental to said needle in the formation ofstitches, feeding mechanism for advancing work across said work-support,a Work-edge indenting element mounted for reciprocation above saidwork-support and crosswise of the line of seam formation in the regionof the path of needle-reciprocation, a driving gear-wheel disposed belowsaid work-support, means for rotating said gear-wheel, operativeconnections with said gear-wheel for rotating said loop-taker, a drivengear in mesh with said driving gear-wheel and rotatably journaled abovesaid work-support, and operative connections with said driven gear-wheelfor reciprocating said Work-edge indenting element.

6. In a sewing machine, in combination, a work-support, stitch-formingmechanism including a reciprocatory needle, work-feeding means, anedge-indenting element disposed above said work-support and mounted forreciprocation crosswise of the line of scam formation in the region ofthe path of needle-reciprocation, a rotary actuating eccentric disposedabove said work-support, means for rotating said eccentric, a pitmanembracing said eccentric, and a twoarmed rocker having one of its armsoperatively connected to said pitman and the other of its armsoperatively connected to said edge-indenting element.

7. In a sewing machine, in combination, a work-support provided with anopening, stitch forming mechanism including a reciprocatory needle,work-feeding means, an edge-indenting element disposed above saidwork-support and mounted for reciprocation crosswise of the line of seamformation in the region of the path of needle-reciprocation, agear-casing depending from said work-support and providing a lubricantchamber, a driving gear-wheel housed by said gear-casing and adapted todip into a supply of lubricant in said chamber, a driven gear in meshwith said driving gear-wheel and extending through said opening in thework-support, actuating mechanism disposed above said work support andoperatively connected for reciproeating said edge-indenting element fromsaid driven gear, and a casing housing said actuating mechanism.

8. In a sewing machine, in combination, a work-support, stitch-formingmechanism including a reciprocatory needle, work-feeding mechanism, anedge-indenting element disposed above said work-support and mounted forre ciprocation crosswise of the line of seam formation in the region ofthe path of needle reciprocation, a rotary actuating eccentric disposedabove said work-support, operative connections with said eccentric forreciprocating said edgeindenting element, casing means above saidworksupport for housing said eccentric and said operative connectionstherewith, a lubricant-supply chamber disposed below said work-support,and means rendered effective upon operation of the machine for rotatingsaid eccentric and for supplying lubricant from said chamber to saidoperative connections with said eccentric.

9. An edge-indenting unit for sewing machines comprising, a frame, areciprocatory slide-bar journaled in said frame, a hem-deflecting bladecarried by one end of said slide-bar, a crossshaft journaled within saidframe crosswise of said slide-bar, an eccentric mounted upon saidcross-shaft for rotation therewith, a pitman embracing said eccentric,means operatively connecting said pitman with said slide-bar for actu-10. In a sewing machine having a frame including a work-support providedwith an opening therein, a reciprocatory needle, and an actuating shaftjournalcd beneath said work-support; the improvement which consists inthe provision of a unitary edge-indenting mechanism removably securedupon said work-support, said unit comprising a frame member, anedge-indenting element mounted within said frame member forreciprocation crosswise of the line of scam formation in the region ofthe path of needle-reciproca tion, a rocker-element mounted upon saidframe member for actuating said edge-indenting element, and meanscarried by said frame for actuating said rocker element, said last namedmeans being adapted to project downwardly through said work-support foroperative connection with said sewing machine actuating shaft.

11. In a sewing machine having a frame including a work-support providedwith an opening therein, a reciprocatory needle, and an actuating shaftjournaled beneath said work-support; the improvement which consists inthe provision of a unitary edge-indenting mechanism removably securedupon said work-support, said unit comprising a frame member, anedge-indenting element mounted within said frame member forreciprocation crosswise of the line of seam formation in the region ofthe path of needle-reciprocation, a cross-shaft mounted within saidframe member, an eccentric mounted upon said crossshaft, meansoperatively connecting said eccentric with said edge-indenting element,and means operatively connected to said cross-shaft, said last namedmeans being adapted to projectdownwardly through said work-supportopening for connection with said sewing machine actuating shaft.

12. In a sewing machine, in combination, a work-support, a reciprocatoryneedle, a presserfoot disposed above said work-support and having asole-plate provided transversely thereof with a work clearance notchwhich divides the Working surface of said sole-plate into forward andrear portions, a pair of feed-dogs disposed in tandem relation directlybelow said presserfoot for operation through said Work-support, saidfeed-dogs being disposed in cooperative work-feeding relation with therespective forward and rear presser-foot sole-plate portions, means toimpart differential feeding movementsto said feed-dogs, a work-edgeindenting element mounted for reciprocation crosswise of the line ofscam formation in the region of said work clearance notch, and means toreciprocate said work-edge indenting element.

13. In a sewing machine, in combination; an apertured work-support, areciprocatory needle, a presser-foot disposed above said work-supportand having a work-clearance notch formed intermediate the ends andtransversely of the soleplate portion thereof so as to divide saidsoleplate into forward and rear portions, said presserfoot beingprovided with a needle-aperture located adjacent said work-clearancenotch, a pair of independently operated feed-dogs disposed in tandemrelation directly below said presser-foot and beneath the upper surfaceof said worksupport, said feed-dogs being disposed in cooperativework-feeding relation with the respective presser-foot sole-plateportions located at either side of said work-clearance notch, awork-edge indenting element mounted for reciprocation crosswise of theline of seam formation and positioned in line with said work-clearancenotch, and means to reciprocate said work-edge indenting element in atimed relation with said needle reciprocations.

14. In a sewing machine, in combination, an apertured worksupport, areciprocatory needle, a presser-foot disposed above said work-supportand having a work-clearance notch formed intermediate the ends andtransversely of the soleplate portion thereof so as to divide saidsoleplate into forward and rear portions, said presserfoot beingprovided with a needle-aperture located adjacent said work-clearancenotch, a pair of feed-dogs disposed in tandem relation directly belowsaid presser-foot and beneath the upper surface of said work-support,said feed-dogs being disposed in cooperative work-feeding relation withthe respective presser-foot sole-plate portions located at either sideof said Work-clear-.

ance notch, means to impart feeding movements to said feed-dogs, saidmeans being adapted to impart a longer feeding stroke to that feed-dogdisposed beneath the forward sole-plate portion of the presser-foot thanto the other feed-dog, a work-edge indenting element mounted forreciprocation crosswise of the line of seam formation and positioned inline with said work-clearance notch, and means to reciprocate saidworkedge indenting lement in a timed relation with said needlereciprocations.

15. In a sewing machine, in combination, an apertured work-support, areciprocatory needle, a presser-foot disposed above said work-supportand having a slot formed intermediate the ends and transversely of thesole-plate portion thereof so as to divide said sole-plate into forwardand rear portions, said presser-foot being provided with aneedle-aperture located adjacent said slot, a work-edge indentingelement mounted for reciprocation crosswise of the line of seamformation and positioned in line with said slot, means to reciprocatesaid work-edge indenting element within said slot in a timed relationwith said needle reciprocations, a pair of feed-dogs disposed in tandemrelation directly below said presserfoot and beneath the upper surfaceof said worksupport, said feed-dogs being disposed in cooperativework-feeding relation with the respective presser-foot sole-plateportions located at either side of said slot, and means to impartfeeding movements to said feed-dogs, said means being adapted to imparta longer feeding stroke to that feed-dog disposed beneath the forwardsole-plate portion of said presser-foot than to the other feed-dog,

16. In a sewing machine, in combination, an apertured horizontalwork-support, a reciprocatory needle, a presser-foot disposed above saidwork-support and being provided with a horizontal work-clearance notchformed intermediate the ends and transversely of the sole-plate portionthereof so as to divide said sole-plate into forward and rear portions,said presser-foot having a vertical slot formed therein adjacent to andin parallelism with said work-clearance notch and a needle aperturedisposed therein adjacent to and rearwardly of said work-clearancenotch, a work-edge indenting element mounted for reciprocation crosswiseof the line of seam formation and positioned in line with said slot,means to reciprocate said work-edg indenting element within said slot ina timed relation with said needle reciprocations, a pair of feed-dogsdisposed in tandem relation directly below said presser-foot and beneaththe upper surface of said work-support, said feed-dogs being disposed incooperative work-feeding relation with the respective presser-footsole-plate portions located at either side of said work-clearance notch,and means to impart feeding movements to said feed-dogs, said meansbeing adapted to impart a longer feeding stroke to that feed-dogdisposed beneath the forward sole-plate portion of said presser-footthan to the other feed-dog.

' FREDRIC W. BREUL.

REFERENCES CITED UNITED STATES PATENTS Name Date Fowler Apr. 9, 1940Number

